The communications regulator announced on Monday that Internet telephony service providers will be able to offer both geographic and non-geographic numbers to their customers.
Geographic numbers will begin with 01 or 02, like today's existing fixed-line telephone numbers. This will allow consumers to shift onto a VoIP service but retain their existing number, or choose another that indicates where they are located.
Non-geographic numbers for VoIP will begin with 056. These will be suitable for people who want to use their Internet telephony service from a number of locations. For example, they could install the necessary software on their laptop and be contactable anywhere over a GPRS or 3G link.
Ofcom predicted that Internet telephony, which it calls voice over broadband, will allow consumers to access features typically seen just in enterprises today -- such as more sophisticated messaging options, video calls and large conference calls.
In a statement, Ofcom chief executive Stephen Carter said that the regulator's first take was to "keep out of the way", while still encouraging the development of new voice services.
This is Ofcom's first significant move in the Internet telephony sector, and it appears to have found broad approval within the industry.
"It's looking quite good so far," said a spokesman for the Internet Service Providers' Association (ISPA), lauding the availability of both geographic and non-geographic numbers. "There was a concern that Ofcom might go with either one or the other. This gives flexibility to users," the ISPA spokesman added.
Ofcom also announced that it will run a public consultation into the tricky question of how functional and reliable a VoIP service should have to be.
Under UK law, any company offering telephony services must adhere to a set of provisions called PATS (publicly available telephone services). This means the service should be able to continue working after a disaster, and that users should always be able to call the emergency services, for example.
Complying with PATS can be expensive. A VoIP provider would have to pay for a gateway to the public PSTN network, which would be more costly than just routing calls over the public Internet.
On top of which, anyone using VoIP over their home PC will not be able to use the service during an electricity blackout (unless they also ran a generator or an uninterruptible power supply).
ISPA has been lobbying hard that VoIP services should not have to comply with PATS. It recently claimed that this would "effectively deliver a death sentence to the UK's emerging VoIP industry".
"The way the UK broadband infrastructure is at present, you need a phone line in order to get a VoIP service," said the ISPA spokesman, arguing that VoIP will not be competing directly with PSTN services.
Ofcom's consultation will run until 15 November.